Joining pipes



1932- I w. H. ARMACOST 50 JOINING PIPES Filed April 17, 1929 I INVENTOR. .4 M/ur ///f/-macasf BY a/iw A TTORNE Y.

Patented Get. 4, 1932 srrEs PATENT OFFICE wiLBna Ramadan, or new YORK, N. Y., ASSIGNOR 1 THE SUPERHEATER COMPANY, on NEW YORK, n. Y.

JOINING PIPES Application filed. April 17, 1929. Serial No. 355,799.

My invention relates to joining pipes and has for its generalpurpose the provision of a novel form of welded joint'by means of whichseparate lengths of pipe may be joined to form a substantially integral structure by means of a forged Weld between the ends of the pipes to be joined.

In the exercise of my invention the ends of the pipes to be joined are placed over an annularmandrel or anvil and forged together to efiect a pressure weld, the mandrel serving to form a support for the plpe ends )ermittin the necessar ressure to be a C L J- plied thereto to effect the weld.

. The invention may best be understood by reference to the accompanying drawing in whichFig. 1 1s, a fragmentary view partly in section showing two pipe ends in posltlon over an anvil ready for welding; Fig. 2 is a view similar to Fig. illustrating the structure shown in Fig. 1 after the weld has been effected; Fig. 3 is a view similar to Flg. l

showing a slightly modified form of structure ready to be welded and Fig. 4 is a view showing the structure illustrated in Fig. 3 after the weld has been efiected.

Referring now to the drawing, there is,

shown'in Fig. 1: two similar pipes 1 and 2 --the ends of which have been flared as at 1 a and 2-a and which are preferably,

' though not necessarily, scarved at l -Z) and 2Z). The pipe ends 1-@ and 2a' are placed in juxtaposed position over an an- 1iular anvil 3 having an internal cylindrical 'gof a sphere although bore, the diameter of which is preferablythe same as the internaldiameter of the pipes 1 and 2. In the form shown the external sur- 7 face of the anvil 3is inthe form of a section this exact external contour is not essential. The anvil 3 is however V In effecting the joint between the pipe ends the ends lea and 2a are preferably first heated to a welding temperature and placed in the position shown in Fig. 1 over the anvil *3. The anvil 3 may be of the same material as that of the pipes 1 and 2, but to prevent the anvil from unduly cooling the heated endsof the pipes after they have been placed in' position and before welding,'itmay be desirable toheat the anvil also. The anvil i does not need to'be heated to the temperature '55 of the pipe ends but in many instances it is desirable to heat it to a temperature where ordinary steel would lose its strength, and in such instances the anvil may be made of some special alloy such for example as high speed tool steel or the-like which retains its normal physical characteristics even when at a temperature of 1,000 degrees F. or more. Such materials are well known and specific analyses thereof are therefore not herein specified. 6:)

After the heated pipe ends and the anvil are placed in the position shown in Fig. 1 the welding may be effected by any desired method which will produce an externally applied pressure acting substantially radially and forcing the pipe ends together to a 'weld' over the anvil. As will be readily apparent the weld may be effected by hand hammering, butfor production purposes mechanical means are preferably employed. Such means may comprisemechanically operated reciprocating hammers under which the tube ends are placed and rotated, the two pipe ends may be held stationary in a suitable die under rotating and reciprocating hammers, so

or the weld may be efiected by rolling the pipe ends under pressure in a variety of specific ways well known to those skilled in the art- The anvil is in no case welded to the pipes during the operation but remains separate from them.

In Fig. 3' aslightly different arrangement for carrying the process into effect is shown. In this form aportion of the exterior surface of the anvil 3-a is made generally eon- 9L ical, with the taper of the conical surface substantially the same as the taper of the flared pipe end 2, thus providing co-operating surfaces adapted to co -act so that the anvil may be conveniently inserted in and held by the pipe end 2 while the end 1 of the other pipe is placed in position and the weld effected.

Ttis also to be noted that as shown'in Fig.

3 the scarving is confined to the end of the i ii' i e pipe land the endsof the two pipes before welding are placed in over-lapping relation so that a'relatively pronounced lap Weld is I eftectedby pipe ends; V While I have shown the anvils 3 and 3a Q as having a maximum-wall thickness greater. than the'wall thickness of the tubes it will be quite evident that this thickness will vary of pressure required to effect a satisfactory 'weld of such, material.

pipe ends may be varied as desired and ifit is desirable to provide an excess of materialat the'pointwhere the weld is made in'creasingthe amountof over-lap.

' finFig. 4, the approximate position of the p [j in the -welded structure there is no defined v line, ofdemarcation between the two pipe ends, which are merged into a substantially unitary whole by the welding prccess, a a

From Figs, 2and 4 it will be seen that the V path through the joined pipes while the ex- \ternal'diameter is only slightlyincreased at the point of juncture, such increase indiamterially less than that shown. in the drawing,

7 material 'havingjexceptionally great strength without danger of e WlCl1I1g process.

carrying the inventionintoeffect will occur 5 embodiments herein shown are therefore not which embraces all that may scope of the appended claims. ifclaim'y '7 v c 1; article oi the class described compris 7 ng, two pipe lengths,'an annular anvil being l at itsrthickest the application of pressure to the 10 p in accordance with the nature of ,the'material 3 forming the pipes to bejoined and the amount I 7 It will further be 1 V evident thatthe amount of over-lapel the i 9 I Ihaveindicated by the lines 4 in F s and respective welds but it will'be obviousfthat 7 completed structure providesfan unobstructed I eter at this point in some instances being Ina-- as for example when the anvil 3 is made of I Many variations i n-jthe specific manner of" tothosel skilled in the a'rt and the illustrative ,to be'. considered as limiting the invention, fall within the ternal diameter of the pipes, the endsof said 7 beingbelow welding tem-Q 7 perature and incompressible under blows and being so placed that its bore is in line with the pipes, and applying percussive blows substantially radially to said ends to "efiect a weld, whereby the pipes are jo nedwith the anvil remaining 1n place and separate from thepipes, v and contour, with the boreat the joint being the same as that of the pipes. V V

Y WILBUR H. ARMAOOST.

this mayreadily be accomplished by suitably andrmaintaining' its original shape 7 and the weld isefl'ected by means of a large number of'relatively lightimpacts so that the I anvil may be of relatively very thin section its collapsing during the 7 portion at least as thick as the I pipes and having-a cylindrical bore the diameter of whichis substantiallythat of thejin-j joiningthe'ends of pipes 1 heating the ends of said- 

